1. Field of the Invention
Printing of wall surfaces and ceiling panels is well known. Obtaining a variety of effects involving several colors as well as a plethora of geometric shapes or decorative patterns is not new. The idea of embossing to obtain the geometrical shapes or decorative patterns followed by a complex process of using differently colored ink plates to provide coating of the valley areas of the embossed product or painstakingly decorating the valley areas of the embossed product has not achieved any significant commercial success. Furthermore, these processes provide non-precise coating of the valleys or, in the case of decorating, provide a process that is difficult to control and, with materials such as woven or non-woven fabrics, is almost impossible to perform.
2. Prior Art
Valley printing, as stated in "Plastics Machinery & Equipment," November 1973, is the application of inks to the tips of an embossing roll to produce three-dimensional fabrics with a wide range of colorful visual effects. The equipment used involves an embossing section, a metering system and a heat source to make the fabric receptive to the embossing. Ink is metered to the embossing roll where it is deposited on the tips of the roll. As the roll comes in contact with the fabric, the ink is delivered to the valleys on the embossed fabric. The ability to meter ink is the heart of the valley printer. If there is too much ink, the valley becomes "flooded"; if there is too little, the pattern appears "washed out". If the valley printer involves three or more colors, the metering problems are multiplied.
U.S. Pat. Nos. 3,399,101, 3,850,095, and 4,135,024 are representative of the complicated methods and equipment used to accomplish valley printing. U.S. Pat. No. 3,399,101 utilizes a unique construction of plastic sheeting wherein the embossing on a concealed surface is printed or decorated but remains visible through the sheet. U.S. Pat. No. 3,850,095 employs a deeply engraved embossing roll and hot melt inks to emboss a fiber carpet while color decorating in the valley areas and sealing the embossed areas in place. U.S. Pat. No. 4,135,024 provides a method of simultaneously strengthening and decorating a low-integrity dry-formed non-woven fibrous web to impart a valley print decorative effect.
Sublimation transfer printing, as described starting on page 240 of "An Introduction to Textile Printing", Clarke, 4th Edition, 1974, is a process pioneered in 1969, often described as "dry dyeing". The process involves the use of dyes, usually disperse dyes which will sublime at temperatures below those which will damage the fabric with which the dyes are in contact. The fabric is one for which the disperse dyes have an affinity. Specifically, all that is required is a supply of suitably printed sublimation transfer paper, a supply of fabric and a heat transfer press. The paper, with its printed surface in contact with the fabric, is placed between the surfaces of the heat transfer press. The press head, at about 400.degree. F. for polyester fabric, is lowered and held for a sufficient time to transfer the dye to the surface of the fabric.